Identification tags have been used for numerous types of animals throughout the years. The original metal clips pressed on the ear of the animal have been replaced with more sophisticated combinations of pins which pierce a portion of the body of the animal, and a tag having a receiving socket through which a portion of the pin enters. The tag, typically formed of a soft plastic, is provided with an indicia receiving surface made integral with a smaller region containing the socket. Typically, the socket is located on the outside of the tag near one end with a hole extending through the tag into the socket. A shoulder is contained within the receiving socket in order to retain a piercing head contained on the pin or shaft urged normally through the animal ear.
A mechanical applicator, similar in respect to a pair of pliers, is typically utilized to urge the piercing head through the body portion of the animal and into the receiving socket in the large area tag. Since the stem or shaft of the attachment device is required to transmit the force from the applicator tool to the body piercing head, the attachment device is rigid. In practice, the attachment device includes the piercing head affixed to a stem or shaft and a base member of larger diameter which directly receives the force from the applicator. The attachment device is formed of a rigid material such as nylon so that the wound created in the ear is not made larger than necessary due to movement of the piercing head during application or misalignment with the receiving socket. When the identification tag is affixed to the animal by the attachment device, an untended wound exists in the adjacent tissue of the animal. In order to promote recovery by the animal from this intentionally inflicted wound, it is desirable to use devices that provide smooth contact surfaces adjacent the exposed tissue.
In the design of an ear tag and associated attachment device, it has been found beneficial to provide a relatively large diameter skirt at the base of the ear piercing attachment device. The skirt is formed of a flexible plastic material and is molded to the base member so as to provide a smooth exterior surface between the stem or shaft and the skirt surrounding the base. This construction reduces the likelihood that the wound will be irritated by ridges or sharp contours in the attachment device. It further provides the opportunity for air flow to occur between the base of the shaft or stem and the adjacent part of the animal and promote healing. In order to secure the flexible skirt to the base of the rigid ear piercing member, a number of transverse holes have been provided in the base so that the molded material flows therethrough to form a unitary structure. While this construction was intended for the purpose of reducing the detachment of the skirt from the stem base during normal use, the flexible material in the small diameter hole stended to fracture thereby weakening the joining of skirt to base. In addition, the design of a mold providing these transverse channels is complex and expensive. Since the base portion is the larger diameter portion of the attachment device, the channels being filled with material are long relative to their diameter. The molding material must flow through and fill the channels in the base portion of the stem which requires high mold pressures and plastic materials having good flow characteristics. These factors add to the cost of manufacture.
As the animal wearing its identification tag moves about its environs, the tag is likely to be engaged by foliage, fences, or other animals. The flexible skirt attached at the base of the stem provides a measure of protection against tearing or ripping from the ear due to the forces encountered. The forces applied to the tag are countered in part by the flexibility of the skirt. Since the skirt is attached in a manner which surrounds the outer surface of the base, flexure of the skirt occurs where it joins the rigid base. Consequently, the edge contour of the rigid base results in a sharp corner being urged against the adjacent flesh of the animal. Frequently, the wound becomes reopened and the danger of infection reappears. This is to be avoided since the wound is untended and the reopening may be unnoticed for long periods.
Accordingly, it is an object of the present invention to provide an attachment device for an animal identification tag containing a rigid stem and base which provides improved and controlled flexibility between the ear piercing member and the retaining skirt affixed thereto. In addition, the present invention is directed to the provision of an attachment device having a skirt formed of flexible material wherein the region of flexure is spaced outwardly from the rigid base thereof. A further object is to provide a structural configuration for an attachment device which eliminates transverse channels to simplify the manufacturing process thereof and provides a durable locking of skirt to the base and stem combination.